JP2006305796A - Treatment method of nozzle plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent disturbance in the ejection direction of ink by a bubble occurring when a water repellent film is formed, and to prevent warpage of a nozzle plate. <P>SOLUTION: A photocurable resin sheet 175 is formed on an ink ejection face 70a of a nozzle plate 30 having a nozzle 8 formed thereon by sticking a conveyance film on the upper face 31 to form a lamination body 179. The lamination body 179 is placed in a vacuum pressurizing device 190 to form a hermetically sealed space 198. Under the condition that the pressure of the hermetically sealed space 198 is reduced to be less than that of the atmospheric air, the photocurable resin sheet 175 is pressed against the nozzle plate 30, and then a part of the photocurable resin sheet 175 is injected into the nozzle 8. The photocurable resin sheet 175 is irradiated with a light through the nozzle 8 to form a pillar type cured section on a portion in the vicinity of the outlet of the nozzle. A part of the photocurable resin sheet 175 which is not cured is removed to disclose an ink ejection face 70a. Finally, a water repellent film is formed on the ink ejection face 70a. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for processing a nozzle plate having nozzle holes for ejecting ink.

  Patent Document 1 describes a surface treatment method for a nozzle plate having a large number of nozzles. In this nozzle plate surface treatment method, first, a photosensitive resin film is laminated on the surface of the nozzle plate, and the photosensitive resin film is pressurized while being heated to a temperature equal to or higher than the glass transition temperature. The part is inserted into the nozzle. Next, ultraviolet rays are irradiated from the back surface of the nozzle plate to cure the portion that has entered the nozzle to form a plug portion, and then the photosensitive resin film other than the plug portion is removed. Then, a plating layer is formed on the surface of the nozzle plate using the plug portion as a mold. Thus, a plating layer that becomes a water repellent film is formed on the surface of the nozzle plate.

Japanese Patent Laid-Open No. 6-246921

  However, in the technique described in Patent Document 1 described above, bubbles are generated from the photosensitive resin film when pressure is applied while heating in order to allow a part of the photosensitive resin film to enter the nozzle. If this bubble stays in the vicinity of the boundary between the plug body and the nozzle, the shape of the plug body varies between the plurality of nozzles. Due to the variation in the shape of the plug body, the shape in the vicinity of the nozzle of the plating layer also varies among the plurality of nozzles, and the discharge direction of the liquid from the nozzle is disturbed. Further, when the photosensitive resin film is heated to the glass transition temperature or higher, the nozzle plate is similarly heated, so that the nozzle plate is warped due to the difference in thermal shrinkage between the nozzle plate and the photosensitive resin film.

  Accordingly, an object of the present invention is to provide a method for treating a nozzle plate that suppresses disturbance in the ink ejection direction and warpage of the nozzle plate due to the generation of bubbles during the formation of a water repellent film.

Means for Solving the Problems and Effects of the Invention

  In the method for treating a nozzle plate of the present invention, a photocurable resin is used so that at least one of the opening ends is closed on the ink discharge surface of the nozzle plate in which one opening end of a nozzle hole for discharging a liquid is formed. Laminating step of laminating sheets, and after the laminating step, the photocurable resin sheet is pressed against the nozzle plate in a state where the peripheral space of the nozzle plate is depressurized from the atmospheric pressure. A filling step of filling a part of the resin sheet into the nozzle hole, and after the filling step, the surface of the nozzle plate from the surface opposite to the ink discharge surface to the photocurable resin sheet through the nozzle hole. A curing step of partially curing the photocurable resin sheet by irradiating with light, and a cured portion of the photocurable resin sheet in the nozzle hole A removal step of removing the uncured portion of the photocurable resin sheet so that the ink discharge surface remains exposed and the ink discharge surface is exposed; and a water repellent film on the exposed ink discharge surface after the removal step And a water-repellent film forming step.

  According to this, a part of the photocurable resin sheet is filled in the nozzle hole in a state where the surrounding space is depressurized from the atmospheric pressure. Since the glass transition temperature of the photocurable resin sheet decreases according to the decompressed state of the surrounding space, the photocurable resin sheet is easily softened without particularly heating the photocurable resin sheet. Part of the sheet can be filled into the nozzle holes. Therefore, bubbles are not generated in the photocurable resin sheet in the vicinity of one opening end (ink outlet) of the nozzle hole, and the shape of the cured portion is stabilized. Therefore, the variation in the shape of the one opening end of the nozzle hole is reduced, so that the disturbance in the ink ejection direction is suppressed. In addition, warpage of the nozzle plate due to the difference in thermal shrinkage between the nozzle plate and the photocurable resin sheet can be prevented.

  In the present invention, in the laminating step, it is preferable that the photocurable resin sheet and the nozzle plate are sequentially integrated between two rollers while being overlapped with each other. According to this, by sandwiching the nozzle plate and the photocurable resin sheet between the rollers, the photocurable resin sheet is attached to the nozzle plate while suppressing air from remaining between the nozzle plate and the photocurable resin sheet. Can be stacked.

  Further, at this time, in the laminating step, the photocurable resin sheet and the nozzle plate are sequentially entered between the two rollers together with a transport film that sandwiches the nozzle plate with the photocurable resin sheet. You may let them. According to this, since the nozzle plate is sandwiched between the photocurable resin sheet and the transport film, both openings of the nozzle holes can be closed. This makes it difficult for dust to enter the nozzle hole. Therefore, in the curing process, the cured portion can be formed while suppressing variations among the plurality of nozzles.

  At this time, in the laminating step, the nip length of the nozzle plate held by the two rollers may be shorter than the maximum length in the longitudinal direction of the nozzle plate. As a result, the nip length of the nozzle plate is relatively short even if there is a slight difference in the pressing force of the nozzle plate by the two rollers at both ends in the axial direction of the roller. The difference in pressing force is reduced. Therefore, almost no air is interposed between the nozzle plate and the photocurable resin sheet.

  Further, in the present invention, in the filling step, the photocurable resin sheet and the nozzle plate are sandwiched between two flat plates, while applying a pressing force to the flat plate, a part of the photocurable resin sheet is It is preferable to fill the nozzle holes. Thereby, a part of photocurable resin sheet can be uniformly filled in a nozzle hole.

  Moreover, in this invention, it is preferable that the temperature of the said photocurable resin sheet and the said nozzle plate shall be 20 degreeC or more and 30 degrees C or less in the said filling process. Thereby, since a photocurable resin sheet becomes the temperature range of 20 degreeC-30 degreeC, the filling amount of the photocurable resin sheet in a nozzle hole can be made substantially constant irrespective of temperature.

  Moreover, in this invention, it is preferable to arrange | position a resin sheet between one said flat plate and the said nozzle plate in the said filling process. As a result, even if there is a slight deviation in the parallelism between the plane contacting the flat nozzle plate and the plane contacting the flat photocurable resin sheet, the deviation is absorbed by the resin sheet. Therefore, the filling amount of the photocurable resin sheet into the nozzle holes can be stabilized.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is an external perspective view of an inkjet head having a nozzle plate that employs a nozzle plate processing method according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line II-II in FIG. As shown in FIG. 1, the inkjet head 1 includes a head main body 70 having a rectangular planar shape extending in the main scanning direction for ejecting ink onto a sheet, and disposed above the head main body 70 and two And a base block 71 in which the ink reservoir 3 is formed.

  As shown in FIG. 2, the head main body 70 includes a flow path unit 4 in which an ink flow path is formed, and a plurality of actuator units 21 bonded to the upper surface of the flow path unit 4 with an epoxy thermosetting adhesive. Is included. Further, a flexible printed circuit (FPC) 50 is joined to the upper surface of the actuator unit 21 and pulled out to the left or right, and the FPC 50 is pulled upward while being bent in FIG.

  FIG. 3 is a plan view of the head body 70 as viewed from above. As shown in FIG. 3, the flow path unit 4 has a rectangular planar shape extending in the main scanning direction. In FIG. 3, the manifold channel 5 provided in the channel unit 4 is drawn with a broken line. The ink stored in the ink reservoir 3 of the base block 71 is supplied to the manifold channel 5 through the plurality of openings 3a. The manifold channel 5 is branched into a plurality of sub-manifold channels 5 a extending in parallel with the longitudinal direction (main scanning direction) of the channel unit 4.

  On the upper surface of the flow path unit 4, four actuator units 21 having a trapezoidal planar shape are arranged and bonded in two rows in a staggered manner so as to avoid the openings 3a. Each actuator unit 21 is arranged such that its parallel opposing sides (upper side and lower side) are along the longitudinal direction of the flow path unit 4. The plurality of openings 3 a are arranged in two rows along the longitudinal direction of the flow path unit 4, and a total of ten openings 3 a in five rows are provided at positions that do not interfere with the actuator unit 21. These openings 3a are arranged in a staggered manner as in the actuator unit 21 as a whole. The oblique sides of the adjacent actuator units 21 partially overlap in the width direction (sub-scanning direction) of the flow path unit 4.

  A large number of nozzles 8 are arranged in a matrix for each area corresponding to the adhesion area of the actuator unit 21 on the ink discharge surface 70a on the bottom surface of the head main body 70 where the nozzles (nozzle holes) 8 having minute diameters are arranged. Arranged to form ink ejection regions. A pressure chamber group 9 in which a large number of pressure chambers 10 (see FIG. 5) are arranged in a matrix is formed on the upper surface of the flow path unit 4 facing the actuator unit 21. In other words, the actuator unit 21 has a dimension that spans a large number of pressure chambers 10 constituting the pressure chamber group 9. The actuator unit 21, the pressure chamber group 9, and the ink discharge region have similar outer shapes.

  Returning to FIG. 2, the base block 71 is made of a metal material such as stainless steel. The ink reservoir 3 in the base block 71 is a substantially rectangular parallelepiped hollow region extending along the longitudinal direction of the base block 71. The ink reservoir 3 is supplied with ink from an ink tank (not shown) installed outside through an opening (not shown) provided at one end thereof, and is always filled with ink. The ink reservoir 3 is provided with a total of ten openings 3b for allowing ink to flow out in two rows along the extending direction. These openings 3 b are provided in a staggered manner so as to be connected to the openings 3 a of the flow path unit 4. That is, the ten openings 3b of the ink reservoir 3 and the ten openings 3a of the flow path unit 4 are provided to have the same positional relationship in plan view.

  The lower surface 73 of the base block 71 protrudes downward from the surroundings in the vicinity 73a of the opening 3b. The base block 71 is in contact with the vicinity of the opening 3 a on the upper surface of the flow path unit 4 only at the vicinity 73 a of the opening 3 b on the lower surface 73. Therefore, a region other than the vicinity 73a of the opening 3b on the lower surface 73 of the base block 71 is separated from the head main body 70, and the actuator unit 21 is disposed in this separated portion. In other words, the lower surface 73 of the base block 71 has the periphery of the opening 3b protruding toward the flow path unit 4 and is in contact with the flow path unit 4 at this protruding portion. In a region other than the protruding portion, the actuator unit 21 and the FPC 50 are disposed in a separated portion formed between the flow path unit 4 leaving a predetermined gap.

  The holder 72 includes a gripping portion 72a that grips the base block 71 and a pair of projecting portions 72b that are provided at intervals in the sub-scanning direction and project upward from the upper surface of the gripping portion 72a. The base block 71 is bonded and fixed in a recess formed on the lower surface of the grip portion 72 a of the holder 72. The FPCs 50 connected to the actuator unit 21 are arranged so as to be along the surface of the protruding portion 72b of the holder 72 via an elastic member 83 such as a sponge after being pulled out from the separation portion formed by the base block 71. A driver IC 80 is installed on the FPC 50 disposed on the surface of the protrusion 72 b of the holder 72. That is, the FPC 50 transmits a drive signal output from the driver IC 80 to the actuator unit 21 of the head body 70, and the actuator unit 21 and the driver IC 80 are electrically joined by soldering.

  A heat sink 82 having a substantially rectangular parallelepiped shape is disposed in close contact with the outer surface of the driver IC 80. Thereby, the heat generated in the driver IC 80 can be efficiently dissipated. A substrate 81 connected to the outside of the FPC 50 is disposed above the driver IC 80 and the heat sink 82. Seal members 84 are filled between the upper end of the heat sink 82 and the substrate 81, and between the lower end of the heat sink 82 and the FPC 50, and dust and ink enter the main body of the inkjet head 1. Is preventing.

  FIG. 4 is an enlarged plan view of a region surrounded by a one-dot chain line drawn in FIG. As shown in FIG. 4, four sub-manifold channels 5 a extend in parallel to the longitudinal direction (main scanning direction) of the channel unit 4 in a region facing the actuator unit 21 in the channel unit 4. ing. A large number of pressure chambers 10 having a substantially diamond shape (rhombus with rounded corners) are formed on the upper surface of the flow path unit 4. In the pressure chamber 10, one acute angle portion communicates with the nozzle 8, and the other acute angle portion communicates with the sub-manifold channel 5 a via the aperture 12. In this way, a large number of individual ink flow paths 7 communicating with each of the nozzles 8 are connected to each sub-manifold flow path 5a. In FIG. 4, in order to make the drawing easy to understand, the pressure chamber 10 (pressure chamber group 9), the aperture 12, and the nozzle 8 that are to be drawn by broken lines below the actuator unit 21 are drawn by solid lines.

  Next, the cross-sectional structure of the head body 70 will be described. FIG. 5 is a cross-sectional view taken along the line V-V shown in FIG. 4 and shows the individual ink flow paths 7. In the present embodiment, the individual ink channel 7 once goes upward and reaches one end of the pressure chamber 10 formed on the upper surface of the channel unit 4. Further, the individual ink flow path 7 is obliquely downward from the other end of the pressure chamber 10 extending horizontally, and is connected to a nozzle 8 formed on the lower surface of the flow path unit 4. As a whole, each individual ink flow path 7 has an arcuate shape with the pressure chamber 10 at the top. This enables high-density arrangement of the individual ink flow paths 7 and realizes a smooth ink flow.

  As shown in FIG. 5, the head main body 70 is a laminated structure including an upper actuator unit 21 and a lower flow path unit 4. Both units 4 and 21 are also configured by laminating a plurality of thin plates. Among these, the actuator unit 21 has four piezoelectric sheets 41 to 44 (see FIG. 8) laminated and electrodes arranged, as will be described in detail later. Of these, only the uppermost layer is a piezoelectric layer having a portion that becomes an active portion when an electric field is applied (hereinafter simply referred to as a “layer having an active portion”), and the remaining three piezoelectric layers do not have an active portion. Inactive layer.

  On the other hand, the flow path unit 4 is configured by laminating a total of nine sheet materials including a cavity plate 22, a base plate 23, an aperture plate 24, a supply plate 25, manifold plates 26 to 28, a cover plate 29, and a nozzle plate 30. .

  The cavity plate 22 is a metal plate in which a large number of substantially rhombic holes constituting the gap of the pressure chamber 10 are provided within the pasting range of the actuator unit 21. The base plate 23 is a metal plate provided with a communication hole between the pressure chamber 10 and the aperture 12 and a communication hole from the pressure chamber 10 to the nozzle 8 for one pressure chamber 10 of the cavity plate 22.

  The aperture plate 24 is a metal plate provided with a communication hole from the pressure chamber 10 to the nozzle 8 in addition to the hole serving as the aperture 12 for one pressure chamber 10 of the cavity plate 22. The supply plate 25 is a metal plate provided with a communication hole between the aperture 12 and the sub-manifold channel 5a and a communication hole from the pressure chamber 10 to the nozzle 8 with respect to one pressure chamber 10 of the cavity plate 22. The manifold plates 26 to 28 are metal plates each provided with a communication hole from the pressure chamber 10 to the nozzle 8 for one pressure chamber 10 of the cavity plate 22 in addition to the sub-manifold flow path 5a. The cover plate 29 is a metal plate provided with a communication hole from the pressure chamber 10 to the nozzle 8 for one pressure chamber 10 of the cavity plate 22. The nozzle plate 30 is a metal plate in which the nozzles 8 are provided for one pressure chamber 10 of the cavity plate 22.

  These nine plates 22 to 30 are stacked in alignment with each other so that the individual ink flow paths 7 as shown in FIG. 5 are formed. In the present embodiment, the nine plates constituting the flow path unit 4 are made of the same metal material, and SUS430 is used. However, the metal plate such as SUS316 or 42 alloy is used. Also good. Moreover, each plate 22-30 may be comprised from a different metal material.

  As is clear from FIG. 5, the pressure chamber 10 and the aperture 12 are provided at different levels in the stacking direction of the plates. As a result, as shown in FIG. 4, in the flow path unit 4 facing the actuator unit 21, the aperture 12 communicating with one pressure chamber 10 is seen in plan view with another pressure chamber 10 adjacent to the pressure chamber 10. It can be arranged at the same position. As a result, the pressure chambers 10 are in close contact with each other and are arranged at a higher density, so that high-resolution image printing is realized by the inkjet head 1 having a relatively small occupation area.

  Next, the nozzle plate 30 will be described below. FIG. 6 is a plan view of the nozzle plate 30. FIG. 7 is an enlarged cross-sectional view of the nozzle plate shown in FIG. As shown in FIG. 6, the nozzle plate 30 has a plurality of ink ejection regions 51 in which the nozzles 8 are adjacently arranged in a matrix corresponding to the actuator unit 21 bonded to the upper surface of the flow path unit 4. In the present embodiment, four ink ejection regions 51 a to 51 d are arranged in two rows in a staggered manner along the longitudinal direction of the nozzle plate 30. Each of the ink ejection regions 51 a to 51 d has a substantially trapezoidal shape in plan view, and the oblique sides of the adjacent regions 51 partially overlap in the width direction of the nozzle plate 30. That is, the ink discharge area 51 is formed so as to overlap the actuator unit 21 and the pressure chamber group 9.

  As shown in FIG. 7, the nozzle plate 30 has a plurality of nozzles (nozzle holes) 8 penetrating in the thickness direction. A nozzle outlet (discharge port) 8a having a diameter of 20 μm is formed at the tip of the nozzle 8 (lower end in FIG. 7). The nozzle 8 has a straight hole 101 having a cylindrical inner surface, a truncated cone-shaped tapered hole 102, and a curved hole 103 connecting the straight hole 101 and the tapered hole 102. In the tapered hole portion 102, the largest diameter end having the largest diameter is connected to the upper surface 31 of the nozzle plate 30, and the smallest diameter end having the smallest diameter is connected to the curved hole portion 103.

  In the cross section including the central axis of the nozzle 8, the curved hole 103 has a connection end A (minimum diameter end of the taper hole 102) and a connection end B (straight hole) with each of the taper hole 102 and the straight hole 101. The tangent lines L1 and L2 at the end portion on the upper surface 31 side of 101 are formed by arcs parallel to the straight lines constituting the tapered hole portion 102 and the straight hole portion 101, respectively. That is, since the tangent line L1 at the connection end A of the curved hole 103 is parallel to the straight line constituting the tapered hole 102, the connection end A does not become an inflection point, and between the tapered hole 102 and the curved hole 103. The inner diameter changes smoothly and continuously. Further, since the tangent line L2 at the connection end B of the curved hole 103 is also parallel to the straight line constituting the straight hole 101, the connection end B does not become an inflection point, and the nozzle in the vicinity of the connection end B of the curved hole 103 The change in the inner diameter of 8 is smooth.

  On the ink discharge surface (lower surface) 70a of the nozzle plate 30, for example, a water repellent film 106 such as nickel plating containing a fluorine-based polymer material such as polytetrafluoroethylene is uniformly formed with substantially the same thickness. If the water-repellent film 106 is formed around the ink outlet 8a in this way, ink or dust is less likely to adhere around the ink outlet 8a, and the ejection direction of the ink ejected from the nozzle 8 is stabilized.

  Next, the actuator unit 21 will be described. 8A and 8B show the actuator unit, in which FIG. 8A is an enlarged cross-sectional view of a portion surrounded by an alternate long and short dash line in FIG. 5, and FIG. 8B is a plan view of an individual electrode. As shown in FIGS. 8A and 8B, the individual electrode 35 is disposed at a position facing the pressure chamber 10, and a main electrode region 35 a formed in the planar region of the pressure chamber 10 in a plan view. The auxiliary electrode region 35 b is connected to the main electrode region 35 a and is formed outside the plane region of the pressure chamber 10.

  As shown in FIG. 8A, the actuator unit 21 includes four piezoelectric sheets 41 to 44 that are formed to have the same thickness of about 15 μm. These piezoelectric sheets 41 to 44 are formed into a continuous layered flat plate (continuous flat plate layer) so as to be disposed across a number of pressure chambers 10 formed in the pressure chamber group 9. Since the piezoelectric sheets 41 to 44 are arranged as a continuous flat plate layer across a large number of pressure chambers 10, the individual electrodes 35 can be arranged on the piezoelectric sheet 41 with high density by using, for example, a screen printing technique. It has become. For this reason, the pressure chambers 10 formed at positions corresponding to the individual electrodes 35 can be arranged with high density, and high-resolution images can be printed. The piezoelectric sheets 41 to 44 are made of a lead zirconate titanate (PZT) ceramic material having ferroelectricity.

  As shown in FIG. 8B, the main electrode region 35a of the individual electrode 35 formed on the uppermost piezoelectric sheet 41 has a substantially rhombic planar shape that is substantially similar to the pressure chamber 10. That is, the corners of the rhombus are formed with smooth curves (for example, arcs). One acute angle portion of the substantially rhomboid main electrode region 35a extends and is connected to the auxiliary electrode region 35b. A circular land 36 electrically connected to the individual electrode 35 is provided at the tip of the auxiliary electrode region 35b. As shown in FIG. 8B, the land 36 faces a region where the pressure chamber 10 is not formed in the cavity plate 22. The land 36 is made of gold containing glass frit, for example, and is formed on the surface of the auxiliary electrode region 35b as shown in FIG.

  A common electrode 34 having the same outer shape as the piezoelectric sheet 41 and a thickness of approximately 2 μm is interposed between the uppermost piezoelectric sheet 41 and the lower piezoelectric sheet 42. Both the individual electrode 35 and the common electrode 34 are made of, for example, a metal material such as an Ag—Pd system.

  The common electrode 34 is grounded in a region not shown. As a result, the common electrode 34 is kept at an equally constant potential in the region corresponding to all the pressure chambers 10, that is, the ground potential in the present embodiment.

  Next, a method for driving the actuator unit 21 will be described. The polarization direction of the piezoelectric sheet 41 in the actuator unit 21 is the thickness direction. That is, the actuator unit 21 has one piezoelectric sheet 41 on the upper side (that is, separated from the pressure chamber 10) as a layer in which the active portion is present and three piezoelectric sheets on the lower side (that is, close to the pressure chamber 10). It has a so-called unimorph type structure in which 42 to 44 are inactive layers. Therefore, when the individual electrode 35 is set to a positive or negative predetermined potential, for example, if the electric field and polarization are in the same direction, the electric field application portion sandwiched between the electrodes in the piezoelectric sheet 41 works as an active portion (pressure generating portion), Shrink in the direction perpendicular to the polarization direction due to the piezoelectric transverse effect.

  In the present embodiment, the portion sandwiched between the individual electrode 35 and the common electrode 34 in the piezoelectric sheet 41 functions as an active portion that generates distortion due to the piezoelectric effect when an electric field is applied. On the other hand, the three piezoelectric sheets 42 to 44 below the piezoelectric sheet 41 are not applied with an electric field from the outside, and therefore hardly function as active parts. Accordingly, a portion of the piezoelectric sheet 41 sandwiched mainly between the main electrode region 35a and the common electrode 34 is contracted in a direction perpendicular to the polarization direction due to the piezoelectric lateral effect.

  On the other hand, the piezoelectric sheets 42 to 44 are not spontaneously displaced because they are not affected by the electric field, and therefore, the piezoelectric sheets 42 to 44 are not displaced in the direction perpendicular to the polarization direction between the upper piezoelectric sheet 41 and the lower piezoelectric sheets 42 to 44. A difference is caused in the distortion, and the entire piezoelectric sheets 41 to 44 try to be deformed so as to protrude toward the non-active side (unimorph deformation). At this time, as shown in FIG. 8A, the lower surface of the actuator unit 21 constituted by the piezoelectric sheets 41 to 44 is fixed to the upper surface of the partition wall (cavity plate 22) that partitions the pressure chamber. Therefore, the piezoelectric sheets 41 to 44 are deformed so as to protrude toward the pressure chamber. For this reason, the volume of the pressure chamber 10 is reduced, the pressure of the ink is increased, and the ink is ejected from the nozzle 8. Thereafter, when the individual electrode 35 is returned to the same potential as that of the common electrode 34, the piezoelectric sheets 41 to 44 return to the original shape and the volume of the pressure chamber 10 returns to the original volume, so that ink is sucked from the manifold channel 5 side. .

  As another driving method, the individual electrode 35 is set to a potential different from that of the common electrode 34 in advance, and the individual electrode 35 is once set to the same potential as the common electrode 34 every time there is an ejection request, and then again individually at a predetermined timing. The electrode 35 can be at a different potential from the common electrode 34. In this case, when the individual electrodes 35 and the common electrode 34 are at the same potential, the piezoelectric sheets 41 to 44 return to their original shapes, so that the volume of the pressure chamber 10 is in an initial state (the potentials of the two electrodes are different). ) And the ink is sucked into the pressure chamber 10 from the manifold channel 5 side. Thereafter, at the timing when the individual electrode 35 is set to a potential different from that of the common electrode 34 again, the piezoelectric sheets 41 to 44 are deformed so as to protrude toward the pressure chamber 10, and the pressure on the ink increases due to the volume reduction of the pressure chamber 10. Ink is ejected. In this way, ink is ejected from the nozzles 8 and the inkjet head 1 is appropriately moved in the main scanning direction to print a desired image on the paper.

  Next, a method for manufacturing the above-described inkjet head 1 will be described with reference to FIG. FIG. 9 is a manufacturing process diagram of the inkjet head 1.

  In order to manufacture the inkjet head 1, components such as the flow path unit 4 and the actuator unit 21 are separately manufactured, and then the components are assembled. First, in step 1 (S1), the flow path unit 4 is produced. In order to produce the flow path unit 4, the plates 22 to 29 except for the nozzle plate 30 among the plates 22 to 30 constituting the flow path unit 4 are etched using a patterned photoresist as a mask. Are formed in each of the plates 22-29. Then, as will be described later, a plurality of nozzles 8 are formed on the metal plate 130 to be the nozzle plate 30 by the punch 151, and the water repellent film 106 is formed on the lower surface (ink ejection surface) 70a of the metal plate 130, and then the individual ink flow Nine plates 22 to 30 aligned so as to form the path 7 are superposed through an epoxy thermosetting adhesive. Then, the nine plates 22 to 30 are pressurized while being heated to a temperature equal to or higher than the curing temperature of the thermosetting adhesive. Thereby, the thermosetting adhesive is cured and the nine plates 22 to 30 are fixed to each other, and the flow path unit 4 as shown in FIG. 5 is obtained. Since each plate 22-30 is formed with the same metal material at this time, since the linear expansion coefficient of each plate 22-30 becomes the same, the flow path unit 4 does not warp to one side.

  On the other hand, to produce the actuator unit 21, first, in Step 2 (S2), a plurality of piezoelectric ceramic green sheets are prepared. The green sheet is formed in advance by taking into account the amount of shrinkage caused by firing. A conductive paste is screen-printed on the pattern of the common electrode 34 on some of the green sheets. Then, while aligning the green sheets using a jig, the green sheet on which the conductive paste is printed with the pattern of the common electrode 34 is superimposed on the green sheet on which the conductive paste is not printed, Two green sheets on which no conductive paste is printed are overlapped thereunder.

  In step 3 (S3), the laminate obtained in step 2 is degreased in the same manner as known ceramics, and further fired at a predetermined temperature. Thereby, the four green sheets become the piezoelectric sheets 41 to 44, and the conductive paste becomes the common electrode 34. Thereafter, the conductive paste is screen-printed on the pattern of the individual electrodes 35 on the uppermost piezoelectric sheet 41. Then, the conductive paste is baked by heat-treating the laminate, and the individual electrode 35 is formed on the piezoelectric sheet 41. Thereafter, gold including glass frit is printed on the individual electrode 35 to form the land 36. In this way, the actuator unit 21 as depicted in FIG. 8 can be manufactured.

  In addition, since the flow path unit preparation process of step 1 and the actuator unit preparation process of steps 2-3 are performed independently, any may be performed first and may be performed in parallel.

  Next, in step 4 (S4), an epoxy-based thermosetting property having a thermosetting temperature of about 80 ° C. on the surface where a large number of recesses corresponding to the pressure chambers of the flow path unit 4 obtained in step 1 are formed. Adhesive is applied using a bar coater. As the thermosetting adhesive, for example, a two-component mixed type is used.

  Subsequently, in step 5 (S5), the actuator unit 21 is placed on the thermosetting adhesive layer applied to the flow path unit 4. At this time, each actuator unit 21 is positioned with respect to the flow path unit 4 so that the active portion and the pressure chamber 10 face each other. This positioning is performed based on positioning marks (not shown) formed on the flow path unit 4 and the actuator unit 21 in advance in the manufacturing process (step 1 to step 3).

  Next, in step 6 (S6), a heating / pressurizing device (not shown) of the flow path unit 4, the laminate of the thermosetting adhesive between the flow path unit 4 and the actuator unit 21, and the actuator unit 21 is not shown. And pressurizing while heating above the curing temperature of the thermosetting adhesive. In step 7 (S7), the laminated body taken out from the heating / pressurizing device is naturally cooled. Thus, the head main body 70 constituted by the flow path unit 4 and the actuator unit 21 is manufactured.

  Thereafter, after the adhesion step of the FPC 50 is performed, the above-described inkjet head 1 is completed through the adhesion step of the base block 71 and the like.

  Subsequently, a manufacturing and processing method of the nozzle plate 30 constituting a part of the above-described flow path unit 4 will be described below. FIG. 10 shows a manufacturing process of the nozzle plate 30, (a) is a diagram showing a state before forming the nozzle on the metal plate, and (b) is a concave portion that becomes the nozzle formed on the metal plate. It is a figure which shows a condition, (c) is a figure which shows the condition where the recessed part was processed and the nozzle was formed in the metal plate.

  First, in order to manufacture the nozzle plate 30, the punch 151 provided in the mold shown in FIG. 10A is moved from the upper surface 31 of the rectangular flat metal plate 130 made of SUS430 (that is, the upper surface of the nozzle plate 30) 31. Type in. The punch 151 has a truncated cone-shaped tapered portion 152 formed on the proximal end side, a cylindrical portion 153 on the distal end side, and a curved surface portion 154 that connects the tapered portion 152 and the cylindrical portion 153.

  At this time, the recesses 140 are formed in the metal plate 130 as shown in FIG. 10B by driving from the punch 151 from the upper surface 31 of the metal plate 130 with a stroke that does not penetrate the metal plate 130. The recess 140 has a tapered hole portion 102, a straight hole portion 101 ′, and a curved hole portion 103 corresponding to the tapered portion 152, the cylindrical portion 153, and the curved surface portion 154 of the punch 151, respectively.

  As shown in FIG. 10B, since the punch 151 is driven into the metal plate 130, the protrusion 131 is inevitably formed on the lower surface of the metal plate 130. The convex portion 131 is removed by machining (for example, grinding) to flatten the lower surface of the metal plate 130, and the ink outlet 8 a is formed on the lower surface of the metal plate 130. At the same time, the lower portion 132 (the metal plate portion below the portion indicated by the broken line in FIG. 10B) where the tip portion of the hole formed by the cylindrical portion 153 of the punch 151 of the metal plate 130 exists is removed. Only the portion corresponding to the straight hole portion 101 is left on the metal plate 130. Thus, the nozzle plate 30 in which the nozzles 8 as shown in FIG. 10C are formed is manufactured.

  Next, the processing method of the nozzle plate 30 will be described below. FIG. 11 is a schematic diagram illustrating a process of attaching a photocurable resin film and a transport film to the nozzle plate 30. FIG. 12 is a process diagram for filling a part of the photocurable resin sheet into the nozzle 8 of the nozzle plate 30. FIG. 13 is a process diagram for forming the water repellent film 106 on the nozzle plate 30.

  In order to form the water-repellent film 106 by treating the nozzle plate 30, first, it is necessary to protect the water-repellent film 106 from being formed in the ink outlet 8 a that influences the ink ejection characteristics or inside thereof. On the contrary, it is necessary to cover other portions with a water repellent film 106 in a desired form. Therefore, the photocurable resin sheet 175 and the nozzle plate 30 are integrated. For example, in the present embodiment, the nozzle plate 30 is sequentially entered into a laminating apparatus 170 as shown in FIG. 11 to form a laminate with the photocurable resin sheet 175. Here, the photocurable resin sheet 175 is pasted on the lower surface (surface on the ink discharge area 51 side) 70a of the nozzle plate 30, and the transport film 176 is pasted on the upper surface (the lower surface in FIG. 11). Laminate 30 (lamination process). The laminating apparatus 170 includes two rollers 171 and 172 arranged at positions facing each other, a winding unit 177 that winds the belt-like photocurable resin sheet 175 and the transport film 176 via the rollers 171 and 172. It has. The two rollers 171 and 172 are arranged so close that the photocurable resin sheet 175 and the transport film 176 are pressed against the nozzle plate 30. As shown in FIG. 11, the wound belt-shaped photocurable resin sheet 175 is wound up while the cover film 178 adhered to the photocurable resin sheet 175 is peeled off by the roller 181, Then, it is wound around the winding unit 177. On the other hand, the wound belt-shaped transport film 176 is wound around the winding unit 177 via the roller 172.

  The nozzle plate 30 is inserted between the two rollers 171 and 172 of the laminating apparatus 170 so that the short side direction is parallel to the axial direction of the rollers 171 and 172, and the two rollers 171 and 172 are rotated. The photocurable resin sheet 175 and the transport film 176 are wound up by the winding unit 177. Thereby, the adhesive surface of the photocurable resin sheet 175 is in close contact with the lower surface 70 a of the nozzle plate 30, and the ink outlets 8 a of all the nozzles 8 are blocked by the photocurable resin sheet 175. At the same time, the transport film 176 is attached to the upper surface 31 of the nozzle plate 30 so as to block all the other openings of the nozzles 8. At this time, the photocurable resin sheet 175 and the transport film 176 are sequentially pressed by the rollers 171 and 172 from one end portion of the nozzle plate 30 to the other end portion, so that the space between the photocurable resin sheet 175 and the nozzle plate 30 is And the air between the conveyance film 176 and the nozzle plate 30 is pushed out sequentially. Further, the photocurable resin sheet 175 and the transport film 176 can be attached to the nozzle plate 30 without any gaps. In addition, even if there is a slight difference in the pressing force against the nozzle plate 30 by the two rollers 171, 172 at both ends in the axial direction of the rollers 171, 172, the width is sandwiched between the two rollers 171, 172. Since the nip length of the nozzle plate 30 (in this embodiment, the width in the short direction of the nozzle plate 30) is minimized, there is almost no difference between the pressing forces of the two rollers 171 and 172 on the nozzle plate 30. Therefore, air is not caught between the nozzle plate 30 and the photocurable resin sheet 175 and between the transport film 176 and the nozzle plate 30. In addition, since the nozzle 8 of the nozzle plate 30 is blocked by the photocurable resin sheet 175 and the transport film 176, dust and the like do not enter the nozzle 8.

  The transport film 176 is made of polyethylene terephthalate resin and does not have adhesiveness, but is adhered to the photocurable resin sheet 175 facing the periphery of the nozzle plate 30 and attached to the upper surface 31 of the nozzle plate 30. It has become. In addition, since the transport film 176 is very thin, almost no air remains between the nozzle plate 30 and the transport film 176, so that the transport film 176 adheres to the nozzle plate 30.

  Next, the photocurable resin sheet 175 and the transport film 176 attached to the nozzle plate 30 are cut along the outer shape of the nozzle plate 30 to expose the outer peripheral side surface of the nozzle plate 30. The laminated body 179 formed by this cutting and in which the photocurable resin sheet 175 and the transport film 176 having substantially the same shape as the outer shape of the nozzle plate 30 are laminated to each other is a vacuum shown in FIG. It arrange | positions in the pressurization apparatus 190. FIG. As shown in FIG. 12A, the vacuum pressurizing apparatus 190 has a stage (flat plate) 191 having a heater inside, a cylindrical partition wall 192 surrounding the stage 191, and the stage 191 and the partition wall 192 fixed. The pedestal 197 and a pressurizing part (flat plate) 193 having a heater therein are included. An annular sealing material 194 is fixed to the outer peripheral side surface of the pressurizing unit 193. As shown in FIG. 12B, when the pressurizing unit 193 moves downward, the pressurizing unit 193 and the partition wall 192 are provided. Seal between. Further, the tip surface (lower surface) 193 a of the pressurizing unit 193 is a plane parallel to the upper surface 191 a of the stage 191. A flexible resin sheet 196 (for example, a rubber member) is disposed on the upper surface 191 a of the stage 191, and the laminate 179 is placed on the resin sheet 196 so that the resin sheet 196 and the transport film 176 are in contact with each other. Deploy.

  Next, as shown in FIG. 12 (b), it is added to the position where the sealing material 194 is disposed between the partition wall 192 and the front end surface 193 a of the pressurizing unit 193 is not in contact with the laminated body 179. The pressure unit 193 is moved downward to form a sealed space 198 surrounded by the partition wall 192, the pressure unit 193, and the mount 197. And it decompresses so that the vacuum degree in the sealed space 198 may be set to about 1000 Pa with the decompression device which is not illustrated. In addition, the photocurable resin sheet 175 has adhesiveness, and is adhered to the nozzle plate 30 by the adhesive force. On the other hand, since the transport film 176 does not have adhesiveness, the air remaining in the nozzle is mainly discharged from between the nozzle plate 30 and the transport film 176.

  Moreover, the photocurable resin sheet 175 in this embodiment has a glass transition temperature of about 70 ° C. under atmospheric pressure. However, the glass transition temperature is reduced to about 30 ° C. by reducing the pressure in the sealed space 198. While maintaining the reduced pressure state in the sealed space 198, the pressurizing unit 193 is lowered to press the photocurable resin sheet 175 against the nozzle plate 30, and the photocurable resin sheet is placed in the nozzle 8 of the nozzle plate 30. A part of 175 is filled (filling step). At this time, even if the ambient temperature of the vacuum pressurizing apparatus 190 is a room temperature level, that is, a temperature range of 20 ° C. or higher and 30 ° C. or lower, the photocurable resin sheet 175 in this embodiment is softened, so 8 is filled. Therefore, the stacked body 179 is not heated by the heaters of the stage 191 and the pressure unit 193. However, if the ambient temperature of the vacuum pressurization apparatus 190 is less than 20 ° C., the laminate 179 is heated by the heaters of the stage 191 and the pressurizing unit 193 so that the temperature range is 20 ° C. or more and 30 ° C. or less at the room temperature level. However, the photocurable resin sheet 175 may be pressed against the nozzle plate 30 by the pressurizing unit 193, and a part of the photocurable resin sheet 175 may be filled in the nozzle 8 of the nozzle plate 30. This is because even if the glass transition temperature is lowered due to the reduced pressure, if the ambient temperature is too low, the required amount of the photocurable resin sheet 175 cannot be filled in the nozzle 8, so the laminate 179 is kept at 20 ° C. It heats so that it may become the temperature range below 30 degreeC, and the photocurable resin sheet 175 is softened. Note that the photocurable resin sheet 175 is too softened under a reduced pressure of 30 ° C. or more, and the change in the filling amount with respect to the pressing force is large, and the workability is also impaired. Thereby, the filling amount of the photocurable resin sheet 175 into the nozzle 8 can be set to a desired amount corresponding to the pressing force of the pressurizing unit 193. In the present embodiment, the thickness of the photocurable resin sheet 175 is made easy to fill the amount of the photocurable resin sheet 175 necessary for forming a columnar cured portion 162 described later in the vicinity of the tip of the nozzle 8. Is equal to or smaller than the inner diameter of the straight hole portion 101 of the nozzle 8.

  Further, since the upper surface 191a of the stage 191 and the tip surface 193a of the pressure unit 193 are parallel planes, the filling amount of the photocurable resin sheet 175 into the plurality of nozzles 8 is not different for each nozzle and becomes uniform. . In addition, since the laminate 179 is placed on the resin sheet 196, even if there is a slight deviation in the parallelism between the upper surface 191a of the stage 191 and the front end surface 193a of the pressure unit 193, the resin sheet 196 The madness is absorbed by flexibility. Therefore, the filling amount of the photocurable resin sheet 175 into each nozzle 8 can be stabilized.

  Next, as shown to Fig.13 (a), the conveyance film 176 is removed from the nozzle plate 30 with which a part of photocurable resin sheet 175 was filled. Then, as shown in FIG. 13B, the photocurable resin sheet 175 is irradiated from the upper surface 31 side of the nozzle plate 30 to the photocurable resin sheet 175 on the lower surface 70a side through the nozzles 8 so as to be photocurable. The resin sheet 175 is cured (curing process). Here, by adjusting the light exposure amount and curing the photocurable resin sheet 175 only in the direction in which the nozzles 8 extend, the photocurable resin sheet 175 partially protrudes from the lower surface 70a of the nozzle plate 30 and A columnar cured portion 162 having a diameter equal to the inner diameter of the ink outlet 8a of the nozzle 8 is formed. At this time, since dust or the like does not enter the nozzle 8 in the filling process, the light passing through the nozzle 8 is not irregularly reflected by dust and the like, and the columnar cured portion having a diameter equal to the inner diameter of the ink outlet 8a. 162 can be formed. For this reason, the shape and size of the columnar cured portion 162 are uniform and do not vary between the plurality of nozzles 8.

  And as shown in FIG.13 (b), uncured parts other than the columnar hardening part 162 among the photocurable resin sheets 175 of the lower surface 70a of the nozzle plate 30 are removed by dissolving with a developing solution, and columnar hardening is carried out. The portion 162 is left protruding from the lower surface 70a of the nozzle plate 30 (removal process). At this time, the base end portion of the columnar hardened portion 162 remains clogged in the tip end portion of the straight hole portion 101 of the nozzle 8. In this state, as shown in FIG. 13C, the lower surface 70a of the nozzle plate 30 is subjected to water repellent plating such as nickel plating containing a fluorine-based polymer material such as polytetrafluoroethylene, so that the thickness is substantially uniform. A water-repellent film 106 having water is formed (water-repellent film forming step). Then, as shown in FIG. 13D, after the water repellent film 106 is formed, the columnar cured portion 162 is dissolved and removed by a stripping solution. Here, the columnar cured portion 162 partially protrudes from the lower surface 70a of the nozzle plate 30 and has a diameter equal to the inner diameter of the ink outlet 8a of the nozzle 8. Therefore, when the columnar cured portion 162 is removed, An opening having the same opening area as the ink outlet 8 a is formed in the film 106 at the position of the nozzle 8. That is, the water repellent film 106 is formed along the opening end of the ink outlet 8a. The water repellent film 106 is formed on the nozzle plate 30 by the processing method of the nozzle plate 30 as described above.

  As described above, according to the processing method of the nozzle plate 30 of the present embodiment, the laminate 179 is disposed in the sealed space (peripheral space) 198 depressurized from the atmospheric pressure, and a part of the photocurable resin sheet 175 is formed. The nozzle 8 is filled. At this time, the glass transition temperature of the photocurable resin sheet 175 also decreases as the pressure decreases. Here, if at least the working environment of the filling process and the apparatus to be used are maintained at a predetermined temperature, for example, room temperature, the photocurable resin sheet 175 of the present embodiment is particularly suitable for the photocurable resin sheet 175. It is possible to fill the nozzle 8 with a predetermined amount of the photocurable resin sheet 175 without heating. Therefore, no bubbles are generated in the photocurable resin sheet 175 in the vicinity of the ink outlet 8a of the nozzle 8, and the shape of the columnar cured portion 162 is stabilized. Therefore, in the water repellent film forming step, the periphery of the nozzle 8 is covered with the water repellent film 106 sharing the opening end of the ink outlet 8a, so that the ink ejection direction is hardly disturbed. Further, since heating is not particularly performed in the filling step, warpage of the nozzle plate 30 due to a difference in thermal contraction rate between the nozzle plate 30 and the photocurable resin sheet 175 (that is, a difference in linear expansion coefficient) is prevented. Can do. In addition, even if the laminated body 179 is heated to a temperature range of 20 ° C. or higher and 30 ° C. or lower as described above, since the temperature itself is at the room temperature level, the thermal contraction rate between the nozzle plate 30 and the photocurable resin sheet 175. The warp of the nozzle plate 30 due to the difference does not occur.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims. For example, the nozzle plate 30 in the above-described embodiment is employed in a line type ink jet head, but may be applied to a serial type ink jet head. Further, the shape of the nozzle formed on the nozzle plate is not limited to the above-described nozzle 8 shape, and for example, the nozzle is formed only by a straight hole extending in a penetrating manner from the upper surface to the lower surface of the nozzle plate. Alternatively, the nozzle may be formed only with a tapered hole portion that tapers from the upper surface to the lower surface of the nozzle plate.

  In the above-described embodiment, the photocurable resin sheet 175 and the transport film 176 are attached to the nozzle plate 30 by the two rollers 171 and 172 of the laminating apparatus 170, but the transport film 176 is not attached. Also good. Furthermore, a photocurable resin sheet may be attached to the lower surface (ink ejection surface) of the nozzle plate without using the laminating apparatus 170. In this case, it is desirable that the nozzle plate and the photo-curable resin sheet be attached without any gaps so that no air remains. Further, when the nozzle plate 30 is inserted between the two rollers 171, 172, the nip length of the nozzle plate 30 is such that the longitudinal direction and the short direction of the nozzle plate 30 intersect the axial direction of the rollers 171, 172. May be smaller than the length of the nozzle plate 30 in the longitudinal direction. Even in this case, the difference in pressing force between the two rollers 171 and 172 with respect to the nozzle plate 30 is reduced to some extent. Therefore, air is less likely to be caught between the nozzle plate 30 and the photocurable resin sheet 175 and between the transport film 176 and the nozzle plate 30, and almost no wrinkles are formed on the photocurable resin sheet 175 and the transport film 176. Does not occur. If there is almost no difference in the pressing force of the two rollers 171, 172 against the nozzle plate 30 at both ends in the axial direction of the rollers 171, 172, the nip length of the nozzle plate 30 is between the two rollers 171, 172. The length of the nozzle plate may be longer than the length of the nozzle plate. In either case, the time for the nozzle plate 30 to pass between the two rollers 171 and 172 is shortened, and the efficiency of the laminating process is improved.

  Further, in the filling step in the present embodiment, the laminate 179 is sandwiched between parallel planes of the tip end surface 193a of the pressurizing part (flat plate) 193 and the upper surface 191a of the stage (flat plate) 191, and a photocurable resin sheet. 175 is filled in the nozzle 8 of the nozzle plate 30. These pressure unit and stage are composed of two rollers, and a laminate 179 enters between these two rollers under reduced pressure to make a photocurable resin. The sheet 175 may be pressed against the nozzle plate 30 and the photocurable resin sheet 175 may be filled into the nozzles 8 of the nozzle plate 30. In addition, the resin sheet 196 is disposed on the stage 191, but when the front end surface 193a of the pressure unit 193 and the upper surface 191a of the stage 191 are surely parallel to each other, the resin sheet 196 is particularly used as the stage. 191 does not have to be arranged.

  Further, in the above-described filling step, as shown in FIG. 12A, when the laminated body 179 is disposed in the vacuum pressurizing apparatus 190, the photocurable resin sheet 175 is opposed to the front end surface 193 a of the pressurizing unit 193. Was arranged to be. However, regarding the arrangement of the laminated body 179, as shown in FIG. 14, the transport film 176 may be opposed to the front end surface 193a. At this time, the photocurable resin sheet 175 is pressed in contact with the flexible resin sheet 196. Therefore, even if there is some unevenness on the surface of the front end surface 193a and the distribution of the pressing force is locally generated, the photocurable resin sheet 175 applies a uniform pressure from the resin sheet 196 regardless of the location. Will receive. Alternatively, even if the lower surface 70 a of the nozzle plate 30 is uneven, the photocurable resin sheet 175 receives a uniform pressure due to the flexible deformation of the resin sheet 196. Thereby, the filling amount of the photocurable resin sheet 175 is surely made uniform regardless of the nozzle position.

1 is an external perspective view of an inkjet head having a nozzle plate that employs a nozzle plate processing method according to an embodiment of the present invention. It is sectional drawing along the II-II line of FIG. FIG. 3 is a plan view of the head body shown in FIG. 2 as viewed from above. FIG. 4 is an enlarged plan view of a region surrounded by an alternate long and short dash line depicted in FIG. 3. It is sectional drawing in the VV line shown in FIG. It is a top view of a nozzle plate. It is an expanded sectional view of the nozzle plate shown in FIG. The actuator unit is shown, (a) is an expanded sectional view of the part enclosed with the dashed-dotted line in FIG. 5, (b) is a top view of an individual electrode. It is a manufacturing process figure of an inkjet head. The manufacturing process of a nozzle plate is shown, (a) is a figure which shows the condition before forming a nozzle in a metal plate, (b) is a figure which shows the condition where the recessed part used as a nozzle was formed in the metal plate. (C) is a figure which shows the condition where the recessed part was processed and the nozzle was formed in the metal plate. It is a schematic diagram which shows the process of affixing a photocurable resin film and a conveyance film on a nozzle plate. It is process drawing with which a part of photocurable resin sheet is filled in the nozzle of a nozzle plate. It is process drawing which forms a water-repellent film in a nozzle plate. The modification of the processing method of the nozzle plate by one Embodiment of this invention is shown, and it is a situation figure when the laminated body is arrange | positioned to the vacuum pressurization apparatus.

Explanation of symbols

1 Inkjet head 8 Nozzle (nozzle hole)
8a Ink outlet (opening)
30 Nozzle plate 31 Upper surface 70a Ink ejection surface (lower surface)
162 Column-shaped cured part (cured part)
171, 172 Roller 175 Photocurable resin sheet 176 Conveying film 191 Stage (flat plate)
193 Pressurizing part (flat plate)
196 Resin sheet 198 Sealed space (peripheral space)

Claims (7)

A laminating step of laminating a photocurable resin sheet on an ink ejection surface of a nozzle plate in which one opening end of a nozzle hole for discharging liquid is formed, so that at least the one opening end is blocked;
After the laminating step, by pressing the photocurable resin sheet against the nozzle plate in a state where the peripheral space of the nozzle plate is depressurized from the atmospheric pressure, a part of the photocurable resin sheet is moved to the nozzle. A filling step for filling the holes;
After the filling step, the photocurable resin sheet is partially irradiated by irradiating the photocurable resin sheet with light through the nozzle holes from the surface opposite to the ink ejection surface in the nozzle plate. A curing process for curing;
A removing step of removing the uncured portion of the photocurable resin sheet so that the cured portion of the photocurable resin sheet remains in the state of being held in the nozzle hole and the ink discharge surface is exposed;
And a water repellent film forming step of forming a water repellent film on the exposed ink discharge surface after the removing step.   2. The nozzle plate according to claim 1, wherein, in the laminating step, the photocurable resin sheet and the nozzle plate are sequentially entered and integrated between two rollers while being overlapped with each other. Processing method.   In the laminating step, the photocurable resin sheet and the nozzle plate are sequentially entered between the two rollers together with a transport film that sandwiches the nozzle plate with the photocurable resin sheet. The method for processing a nozzle plate according to claim 2.   4. The nozzle plate according to claim 2, wherein, in the laminating step, a nip length of the nozzle plate held by the two rollers is shorter than a maximum length in a longitudinal direction of the nozzle plate. Processing method.   In the filling step, while pressing the photocurable resin sheet and the nozzle plate between two flat plates, a pressing force is applied to the flat plate to fill a part of the photocurable resin sheet into the nozzle hole. The processing method of the nozzle plate of any one of Claims 1-4 characterized by these.   In the said filling process, the temperature of the said photocurable resin sheet and the said nozzle plate shall be 20 degreeC or more and 30 degrees C or less, The processing method of the nozzle plate of any one of Claims 1-5 characterized by the above-mentioned.   The method of processing a nozzle plate according to claim 1, wherein a resin sheet is disposed between the one flat plate and the nozzle plate in the filling step.

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